Receiver for electromagnetic waves.



R. A. vFLSSENDEN. nncmvnn ron ELEOTROMAGNETIQ WAVES.

APPLIOATIOI FILED HAB- 16,1906

Patented June 21,

PATENT OFFICE;

REGINALD A. FESSENDEN, WASHINGTON, DISTRICT OF COLUMBIA.

RECEIVER FOR ELECTROMAGNETIC WAVES.

Specification of Letters Patent. Patented J un 21, 1910,

Application filed March 16, 1906. Serial 1 70 306,388.

T all whom it may concern:

Be it known that I, REGINALD A. FESSEN- DEN, a citizen of the United States, and resident of Washington, District of Columbia, 'haye invented certain new and useful Improvements in Receivers for Electromagnetic Waves,.of which the following is a specification. v

The invention described herein relates to receivers for electro-magneticwaves' of the liquid barretter type,cspecially of that class or kind which may convenientl be termed the self exciting type in which the terminals "of the barretter form respectively the positive and negative elements of a cell for producing the ocal current.

One means commonly'used for producing the voltage for the barretter is a potentiometer. Another means consists in forming the large terminal of the liquid barretter of zinc. The latter however is objectionable as hydrogen will come off at the fine point or terminal thus rendering the barretter less sensitive.

In the accompanying drawin forming a part of this specification, the in section a convenient arrangement of the cell and its-mode of mounting and connections.

.In the practice of m invention the fine -terminals 6 and 7 are ormed of Wollaston wire having its'platinum core in good electrical contact with the electrolyte, as by projecting into such electrolyte, which is contained in a suitable receptacle 2. Suclr terminals are operatively connected in any suitablemanner either directly or indirectly with the aerial 3. The otheyielectrode 10, which is immersed in the -electrolyte,"may

be formed of any suitable material, but

practice that with a receiver constructed in this manner, the tuning is more sharp and better results are' obtained. Other materials may "be employed, as for example, the electrode 10 may be formed of lead perox d in which case twenty per cent. nitr c acid gure shows referably emor twenty per cent. sulfuric acid may be used as an electrolyte. The electrode or terminal 10 is connected to ground, and the indicating mechanism 11 as a telephone, is connected to the terminalsfi, 7 and 10.

In practice I prefer to use two fine terminals, 6 and 7, formed by platinum or referably osmium or iridium or their al- 0 s, passing through glass points, 8 and 9. e fine terminal wire may be flush with the ends of the points or project beyond the same.- These fine terminals are connected either directly or inductively to the aerial 3. The'large electrode 10 which may be formed as heretofore stated is connected to ground. A double telephone 11, preferably of the head type is connected as shown to the terminals, 6, 7 and 10. 16, 16 are inductances or resistances preferably adjustable.

It has been found advisable to maintain the liquid barretter at-a constant temperature, and to that end it is referabl inclosed in a box or shell 12 ormed 0 any suitable material. If the case or shell is formed of metal, the connections leading to the aerial to ground, etc., ,should pass through bushings of insulating material.

The temperature in the box can be kept constant by suitable cooling or heating meansas for example a heating coil 13 arranged in the box and connected to a generator 14,

and controlled by athermostat 15. When the box-or shell is used, the telephone may be so arranged that the indications may be heard through an opening in the box; or the telephone connection may be passed through insulating bushin locatin the telephone outside as shown in dotted mes;

I claim herein as my invention 1. Areceiver for wireless telegraphy,comprising a body of electrolyte, two fine ter minals in contact therewlth and a larger terminal also in contact therewith, combined with circuitsfor passing electromagnetic waves through the electrolyte, and resulting changes of 'ineans for indicatin conductivity in the electrolyte 2. A liquid barretter having. two fine terminals, a large terminal and an electrolyte. In testimony whereof, I have hereunto set my hand and seal, the 12th day of March REGINALD A. ressrrnrr. [a s.]

Witnesses:

Jnssra E. BENT, PHILIP Pos'r. 

